1. Field of the Invention
This invention relates to powered air purifying respirators. In one of its aspects, the invention relates to a powered air purifying respirator that has an integrated plenum and belt. In another of its aspects, the invention relates to a powered air purifying respirator that has a powered air supply source that is adapted to be worn around the waist. In yet another of its aspects, the invention relates to a powered air purifying respirator component that is adapted to be removably mounted to a hose that is connected to a respirator mask. In yet another of its aspects, the invention relates to a powered air purifying respirator component that delivers a constant flow of purified air to a respirator mask in the event of partial filter clogging. In another of its aspects, the invention relates to a kit for a powered air purifying respirator that is adapted for multiple different conditions.
2. Description of the Related Art
Powered air-purifying respirators (PAPRs) continually supply positive air pressure to a respirator mask to maintain positive pressure in the respirator. PAPRs are generally used in military, industrial or hazardous environments to provide personal respiratory protection by preventing ambient air from entering the user's mask, helmet, or hood. Respiratory hazards can include particulate matter, harmful gases, or vapors, which are removed by passing ambient air through the PAPR. Typically, a PAPR includes a powered fan that forces ambient air through one or more filters for delivery to an inlet opening in the respirator mask, helmet or hood. The fan, filter, and power source may be mounted on a face mask or, in some cases, may be mounted on a belt or backpack and connected to the facemask through a hose and a fan. PAPRs that are worn on the user's waist are typically attached to a belt by threading the belt through loops or slots in the component housing, and the respiratory components are typically worn on the back portion of the belt.
International Patent Application No. WO 2006/108042 to Phifer et al. discloses a PAPR that includes an enclosure, defining a single contiguous enclosed interior, an inlet duct, including an inlet and a distribution portion, that guides ambient air to the interior of the enclosure, a plurality of filter canisters disposed within the interior of the enclosure, and a blower that forces air through the at least one inlet, into the interior of the enclosure and through the plurality of filter canisters to produce filtered air suitable for breathing. The main body of the PAPR is the PAPR housing, which encloses the motor, the blower and at least part of the controller. The PAPR housing provides the primary structure of the PAPR and includes one or more ports for the filter canisters. Each armored filter includes a filter canister and a filter cover. Together, the filter covers and manifolds form enclosures that protect the filter canisters from heat, flame, physical blows, etc. The PAPR can be carried by the users around their waist via a belt, or on their back or over their shoulder using a simple conventional shoulder strap or harness, or any other suitable apparatus.
United States Patent Application Publication No. 2006/0191533 to Brookman et al. discloses a combination SCBA system for providing bottled air and PAPR system for purifying ambient air for use by a user wherein the two systems are used alternatingly depending on the contaminated condition of the ambient air and the oxygen content of the ambient air. The blower motor and fan assembly is operatively connected to a plenum chamber assembly that has attached to it a plurality of filter elements. The impeller fan draws ambient air through the filters. The cleaned air is drawn by the fan into operative relationship with the face mask and thereby provides breathable air to the wearer. The system is worn on a conventional harness.
U.S. Pat. No. 4,478,216 to Dukowski discloses a portable breathing assist, including a two part external housing comprising a first half and a second half. The breathing assist further includes an internal scroll housing with a radial impeller within the scroll housing; the radial impeller is mounted so as to be rotatable by the electric motor shaft to which it is attached. An air manifold within the external housing defines a passageway for air from two openings to a central inlet into the internal scroll housing. The air passageway communicates with a plenum which communicates directly with a circular threaded opening adapted to receive a filter pad. The first housing half has brackets for threading a belt therethrough; the belt is said to secure the device around the waist of the user. The first housing half also contains a battery pack. The portable breathing assist is said to be used in conjunction with a face mask and hose.